Jeffrey Quad

Production of the Jeffrey Quad four wheel drive truck
began in 1913 at the Thomas B. Jeffrey factory in Kenosha Wisconsin.

Some thousands of Quads were produced from 1914 for use
in World War I, as transporters and as ambulances,
four wheel drive being invaluable in the quagmires of the war.
In 1916 the firm was sold to Nash which continued to build
the four wheel drive as the Nash Quad.

This 1915 Jeffery Quad is fitted with a 4-cylinder Buda
motor of 4.87 litres. The gearbox has four forward ratios,
plus reverse, and drives front and rear differentials.

Front and rear axles are dead in that they simply carry the weight
of the truck from the semi elliptical leaf springs to the road wheels.
The Meuhl differentials and half-shafts are mounted above the load bearing
dead axles and drive the hubs through hub-reduction gearing.
This reduces the loads on the drive train and gets the differentials and
half shafts up high and out of harm's way. The Meuhl differentials
are essentially equivalent to the modern Torsen type of limited slip
differential incorporating worm gears to drive the differential side gears.
This is high-tech stuff.

The grid fitted to the front of the truck protects the
radiator mounted immediately behind it.

This particular Jeffrey Quad, like many others, became surplus
to requirements after the war and was acquired for use at
the Le Mans race track in 1919. It was used there until
abandoned in 1952. Richard Peskett subsequently heard of it, bought
it and restored it to its present condition.